Macro- and microfossils from the Upper Cretaceous sedimentary rocks of Hornby Island, British Columbia, Canada by Sandy Melvin Stuart McLachlan B.A., University of Victoria, 2010 CRMP, University of Victoria, 2013 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in the School of Earth and Ocean Science Sandy Melvin Stuart McLachlan, 2017 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. ii Macro- and microfossils from the Upper Cretaceous sedimentary rocks of Hornby Island, British Columbia, Canada by Sandy Melvin Stuart McLachlan B.A., University of Victoria, 2010 CRMP, University of Victoria, 2013 Supervisory Committee Dr. Vera Pospelova, Co-Supervisor, (School of Earth and Ocean Sciences) Dr. Richard Hebda, Co-Supervisor, (School of Earth and Ocean Sciences) Dr. Eileen van der Flier-Keller, Departmental Member (School of Earth and Ocean Sciences) iii Abstract Heteromorph ammonites and dinoflagellate cysts from the Upper Cretaceous Northumberland Formation on Hornby Island, British Columbia, Canada are examined. The collection and preparation of new material has enabled the recognition of eleven species of which only three have been reported from the locality. Of these taxa represented from three heteromorph ammonite families in the study area, five are new occurrences and three are new to science. This expansion of the Hornby Island ammonite fauna is presented alongside a pioneering taxonomic survey of dinoflagellate cysts from the same rocks. Together, these macro- and microfossils reinforce a late Campanian age for the Northumberland Formation with the upper extent of the section approaching the Campanian-Maastrichtian boundary (CMB) interval. The palaeoecology and evolutionary relationships of these heteromorph ammonoids are considered with new insights into their ontogenetic development and neritic palaeoenvironmental circumstances. The dinoflagellate cysts and associated terrestrial palynomorphs have also allowed for enhanced palaeoenvironmental reconstruction and depositional setting inference. The scope of the studied material, and the presence of key index taxa, enables refined biostratigraphy and a stronger basis for correlation of the Hornby Island succession with neighboring coeval biotic provinces. iv Table of Contents Supervisory Committee .................................................................................................................. ii Abstract .......................................................................................................................................... iii Table of Contents ........................................................................................................................... iv List of Tables ................................................................................................................................. vi List of Figures ............................................................................................................................... vii List of Plates ................................................................................................................................. xii Dedication .................................................................................................................................... xxi Chapter 1 Introduction.................................................................................................................. 1 1.1 Thesis structure .................................................................................................................... 1 Chapter 2 Reassessment of the late Campanian (Late Cretaceous) heteromorph ammonite fauna from Hornby Island, British Columbia, with implications for the taxonomy of the Diplomoceratidae and Nostoceratidae ........................................................................................ 2 2.1 Contribution of authors ........................................................................................................ 2 2.2 Abstract ................................................................................................................................ 2 2.3 Introduction and geological setting ...................................................................................... 3 2.4 Materials and methods ......................................................................................................... 9 2.5 Institutional abbreviations .................................................................................................. 12 2.6 Morphological abbreviations ............................................................................................. 12 2.7 Systematic Palaeontology .................................................................................................. 12 2.7.1 Family Baculitidae Gill, 1871 ..................................................................................... 13 2.7.2 Family Diplomoceratidae Spath, 1926 ....................................................................... 19 2.7.3 Family Nostoceratidae Hyatt, 1894 ............................................................................ 58 2.8 Discussion .......................................................................................................................... 88 2.9 Summary ............................................................................................................................ 91 2.10 Acknowledgments ........................................................................................................... 92 Chapter 3 General Discussion .................................................................................................... 93 3.1 Heteromorph ammonite taphonomy .................................................................................. 93 3.2 Heteromorph ammonite polymorphism ............................................................................. 95 3.3 Heteromorph ammonoid ontogeny and palaeoecology ..................................................... 98 3.4 Heteromorph ammonoid evolutionary progression ......................................................... 101 3.5 Heteromorph ammonoid palaeobiogeography ................................................................. 103 v Chapter 4 Late Campanian (Late Cretaceous) dinoflagellate cysts from Hornby Island, British Columbia with implications for Nanaimo Group biostratigraphy and palaeoenvironmental reconstructions ........................................................................................................................ 106 4.1 Abstract ............................................................................................................................ 106 4.2 Materials and methods ..................................................................................................... 106 4.3 Morphological abbreviations ........................................................................................... 114 4.4 Systematic Palaeontology ................................................................................................ 114 4.5 Discussion ........................................................................................................................ 168 4.5.1 Age interpretation ..................................................................................................... 168 4.5.2 Dinoflagellate cyst zones .......................................................................................... 171 4.5.3 Palaeoenvironmental and paleolatitudinal reconstructions ....................................... 172 4.6 Acknowledgments ........................................................................................................... 177 4.7 Taxonomic entities ........................................................................................................... 177 Chapter 5 Conclusion ............................................................................................................... 182 5.1 Summary of research ....................................................................................................... 182 References .................................................................................................................................. 183 Appendix I List of heteromorph ammonite specimens ............................................................. 233 Appendix II Heteromorph ammonite specimen measurements ............................................... 254 Appendix III Nostoceras (Nostoceras) species ........................................................................ 266 Appendix IV Glossary of heteromorph ammonite terms .......................................................... 271 Appendix V Palynological counts data ..................................................................................... 274 Appendix VI Palynomorph relative abundances ...................................................................... 277 vi List of Tables Table 2.1. Dichotomous key for identification of species belonging to the genus Solenoceras Conrad, 1860. .................................................................................................................... 51 Table 2.2. Qualitative and quantitative characters applicable to the description of helical whorls belonging to species within the genus Nostoceras